(1) Field of the Invention
The present invention broadly relates to packages of a product such as foods which are to be preserved in fresh state, such as packages of confectionary, coffee beans, ground coffee, powdered milk, soybean flour, powders of cereals, beans, rice, rice cakes, hams, sausages and so forth. More particularly, the present invention is concerned with a method of and an apparatus for packaging a freshness keeping agent in a package together with a food to be preserved in fresh state.
(2) Description of the Related Art
Freshness keeping agents such as de-oxidizing agent and drying agent have been used for the purpose of preserving various foods in fresh state. Usually, these freshness keeping agents are charged in small sacks which are put in a package of a food to be preserved without being fixed to the package.
In the field of food industries, various problems have been encountered due to the fact that the sack of the freshness keeping agent is free within a food package. For instance, there is a risk for the purchaser to take the freshness keeping agent for the edible content and eat the agent. In the industrial processing of foods in which the packages of foods are handled automatically, there is a fear that the freshness keeping agent is dangerously mixed with the foods when the packages are opened. More specifically, in the automatic grinding of coffee beans, there is a possibility that the freshness keeping agent is inadvertently put into a grinder together with the coffee beans so as to be ground and mixed in the ground coffee. Similarly, in the case of automatic cooking of beans, there is a fear that the freshness keeping agent is cooked together with the beans so as to contaminate the cooked beans.
In order to avoid such accidents or troubles, it has been proposed to fix the sack of a freshness keeping agent to the package. For instance, attempts have been made to fix the sack of the freshness keeping agent to the sealing portion of a food package or to fix the sack to a suitable portion of the wall of the package or container by means of an adhesive. These attempts, however, are still unsatisfactory in that the work for fixing the sack is quite laborious and seriously impairs the efficiency of the packaging operation.